Why mole is called fundamental unit.

Spend time observing or thinking about events that involve matter and energy. which events can you explain? which events can’t you explain?

Atrain departs from its station at a constant acceleration of 5 m/s. what is the speed of the train at the end of 20s?

Figure 9 on page 362 shows various motions of balls. the curved path followed by the yellow ball in b in picture b is result of a) inertia b) centripetal motion c) gravity and horizontal velocity d) linear motion